//
//  MainViewController.swift
//  XinLangWeiBo
//
//  Created by lei on 17/2/10.
//  Copyright © 2017年 lei. All rights reserved.
//

import UIKit

class MainViewController: UITabBarController {
    //MARK: - 监听方法
    /// 点击撰写按钮
    @objc private func clickComosedButton()  {
        print("点我了")
    }
    //MARK: - 视图生命周期函数
    override func viewDidLoad() {
        super.viewDidLoad()
   
        addChildViewControllers()
        
        print(tabBar.subviews)
        
        setupComposedButton()
        
    }
    
    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)
        
        // 将按钮设置到顶部
        tabBar.bringSubviewToFront(composedButton)
        
    }
    
    // MARK: - 懒加载控件
    private lazy var composedButton: UIButton = UIButton(
        imageName: "tabbar_compose_icon_add",
        backImageName: "tabbar_compose_button" )


}

// MARK: - 设置界面
extension MainViewController {
    
    /// 设置撰写按钮
    private func setupComposedButton() {
   
        // 1. 添加按钮
        tabBar.addSubview(composedButton)
        
        // 2. 调整按钮
        let count = childViewControllers.count
        
        let w = tabBar.bounds.width / CGFloat(count) - 1
        
        composedButton.frame = CGRectInset(tabBar.bounds, 2 * w, 0)
        
        // 3. 添加监听方法
        composedButton.addTarget(self, action: #selector(MainViewController.clickComosedButton), forControlEvents: .TouchUpInside)
        
    }
    
    // 添加所有的控制器
    private func addChildViewControllers() {

    addChildViewController(HomeTableViewController(), title: "首页", imageName: "tabbar_home")
        addChildViewController(MessageTableViewController(), title: "消息", imageName: "tabbar_message_center")
        addChildViewController(UIViewController())
        addChildViewController(DiscoverTableViewController(), title: "发现", imageName: "tabbar_discover")
        addChildViewController(ProfileTableViewController(), title: "我", imageName: "tabbar_profile")
        
        
    }
    
 
    /// 添加控制器
    ///
    /// - parameter vc:        vc
    /// - parameter title:     标题
    /// - parameter imageName: 图像名称
    private func addChildViewController(vc: UIViewController, title: String, imageName: String) {
        
        // 设置标题
        vc.title = title
        
        // 设置图像
        vc.tabBarItem.image = UIImage(named: imageName)
        
        // 导航控制器
        let nav = UINavigationController(rootViewController: vc)
        
        addChildViewController(nav)
        
    }
    
}
